Debugging requires a multifaceted solution

PROLOGUE: Over the weekend, I was thinking about a recent visit I had with an advanced ASIC team manager who told me that they had optimized most aspects of their verification flow to such an extent that most of their remaining effort was spent in debugging. So, I decided to work up a draft blog on debugging. However, this morning, when I was preparing to post my blog, I noticed that Richard Goering had beat me to the punch and had posted a blog on debugging about two weeks ago. Having reviewed his blog, I think we are both in agreement—debugging is a huge bottleneck in the flow. I think that debugging must be looked at as a solution, and not a tool feature. However, there are many aspects of debugging beyond traditional simulation triage of design models and testbench components—ranging from embedded software, to power and performance analysis, to code and functional coverage closure, etc. There really isn’t a unified solution—debugging must be considered an integral part of each aspect of design and verification.

ACT 1:  My original blog from this weekend….

“Bloody instructions, which, being taught, return to plague the inventor….”

William Shakespeare, Macbeth, act 1, scene 7

All right, even Shakespeare had issues with debugging. But before I get into all of that, let me set the stage with a little background info…

First, let me say that I love my job. My role at Mentor Graphics consists of a diverse set of tasks. Yet, probably my most rewarding work involves studying and assessing today’s electronics industry. The objective of this work is to help Mentor identify discontinuities in today’s EDA solutions, as well as understand emerging verification challenges. But what I like most about my work is that it allows me to participate in detailed discussions with various project teams and multiple industry thought leaders across multiple market segments.

A couple of years ago, I was performing a detailed verification assessment for an ASIC project team. As I usually do when I conduct these kinds of assessments, I asked the team what was the biggest bottleneck in their flow. This one enthusiastic, young engineer started waving his hand vigorously at me and said: “I know, I know…..it’s layoffs!” Okay, so after the group recovered itself from an outburst of nervous chuckles, I pressed forward with my question. It turned out that the group unanimously agreed that debugging was generally a significant, yet often underestimated, effort associated with their flow. Perhaps this shouldn’t surprise anyone, when you consider that the Collett International 2003 IC/ASIC Design Closure study found that 42 percent of the verification effort was consumed in writing test and creating testbenches, while 58 percent was consumed in debugging. More recently, a 2007 Farwest Research study, chartered by Mentor Graphics, found that 52 percent of a dedicated verification engineers effort was consumed in debugging.

Debugging Effort

Debugging Effort

The problem with debugging is that the effort is not always obvious since it applies to all aspects of the design and verification flow and often involves many different stakeholders. For example, architectural modeling, RTL coding, testbench implementation, transaction modeling, embedded software, coverage modeling and closure, and on and on and on. What makes it particularly insidious is that it is extremely difficult to predict or schedule. In fact, what you will find is that a mature organization relies on historical data extracted from their previous project’s debugging effort metrics in order to estimate their future project effort. However, due to the unpredictable nature of debugging, history doesn’t always repeat itself. And unfortunately, there is no silver bullet in terms of a single debugging tool or strategy. Multiple solutions, ranging from RTL implementation debugging, to OVM object-oriented testbench component debugging, to embedded software debugging capabilities, to coverage closure are required. Fortunately, multiple good solutions have emerged, ranging from assertions for reducing RTL debugging effort, to SystemVerilog dynamic structures analysis and debugging, to processor-driven verification debugging solutions for embedded software verification, to the intelligent testbench for automating coverage closure.

EPILOGUE: I opened this blog humorously with a quote from Shakespeare. Yet, today’s debugging effort is no laughing matter, and it contributes significantly to a project’s overall design and verification effort. I’ll conclude this blog with a sobering quote from Brian Kernighan (the K in the K&R C language) who once pointed out:

Debugging is twice as hard as writing the code in the first place.

I’m curious about your thoughts. Does debugging consume a significant amount of effort in your flow? If not, what is the biggest bottleneck in your flow?

Post Author

Posted January 6th, 2010, by

Post Tags

, ,

Post Comments

1 Comment

About Verification Horizons BLOG

This blog will provide an online forum to provide weekly updates on concepts, values, standards, methodologies and examples to assist with the understanding of what advanced functional verification technologies can do and how to most effectively apply them. We're looking forward to your comments and suggestions on the posts to make this a useful tool. Verification Horizons BLOG

@dennisbrophy Tweets

  • Loading tweets...

@dave_59 Tweets

  • Loading tweets...

@jhupcey Tweets

  • Loading tweets...

Comments

One comment on this post | ↓ Add Your Own

Commented on January 8, 2010 at 9:29 am
By Jason

Just to check how important debugging is, I searched cadence.com and found out that the word “debugging” appears in 19 of 55 blog posts I have written. It must be pretty important.

It doesn’t matter if you are a hardware design engineer, verification engineer, or embedded software engineer, we all know the daily cycle of “code, compile, run, debug” and that debug is the most tedious.

Finding your own bugs is hard, finding bugs inserted by other people is even harder.

The good news is there are a lot of ways to find bugs, the bad news trying to decide which technique should be used for a specific problem.

Jason
http://www.cadence.com/community/posts/jasona.aspx

Add Your Comment

Archives

October 2014
  • DVCon India: A Smashing Hit!
  • September 2014
  • Portable and Productive Test Creation with Graph-Based Stimulus
  • Supporting A Season of Learning
  • August 2014
  • DVCon Goes Global!
  • Better Late Than Never: Magical Verification Horizons DAC Edition
  • July 2014
  • Accellera Approves UVM 1.2
  • May 2014
  • Getting More Value from your Stimulus Constraints
  • The FPGA Verification Window Is Open
  • April 2014
  • UVM DVCon 2014 Tutorial Video Online
  • Mentor Enterprise Verification Platform Debuts
  • March 2014
  • New Verification Academy ABV Course
  • DVCon 2014 Issue of Verification Horizons Now Available
  • February 2014
  • DVCon–The FREE Side
  • More DVCon–More Mentor Tutorials!
  • UVM 1.2: Open Public Review
  • DVCon 2014: Standards on Display
  • Just because FPGAs are programmable doesn’t mean verification is dead
  • January 2014
  • Managing Verification Coverage Information
  • November 2013
  • Epilogue: The 2012 Wilson Research Group Functional Verification Study
  • New Verification Horizons Issue Available
  • October 2013
  • Happy Halloween from ARM TechCon
  • IEEE Standards Association Symposium on EDA Interoperability
  • STMicroelectronics: Simulation + Emulation = Verification Success
  • September 2013
  • A Decade of SystemVerilog: Unifying Design and Verification?
  • Part 12: The 2012 Wilson Research Group Functional Verification Study
  • August 2013
  • Part 11: The 2012 Wilson Research Group Functional Verification Study
  • Part 10: The 2012 Wilson Research Group Functional Verification Study
  • Part 9: The 2012 Wilson Research Group Functional Verification Study
  • Part 8: The 2012 Wilson Research Group Functional Verification Study
  • July 2013
  • Part 7: The 2012 Wilson Research Group Functional Verification Study
  • Walking in the Desert or Drinking from a Fire Hose?
  • Part 6: The 2012 Wilson Research Group Functional Verification Study
  • A Short Class on SystemVerilog Classes
  • Part 5: The 2012 Wilson Research Group Functional Verification Study
  • Part 4: The 2012 Wilson Research Group Functional Verification Study
  • June 2013
  • Part 3: The 2012 Wilson Research Group Functional Verification Study
  • Part 2: The 2012 Wilson Research Group Functional Verification Study
  • May 2013
  • Texas-Sized DAC Edition of Verification Horizons Now Up on Verification Academy
  • IEEE 1801™-2013 UPF Standard Is Published
  • Part 1: The 2012 Wilson Research Group Functional Verification Study
  • What’s the deal with those wire’s and reg’s in Verilog
  • April 2013
  • Getting AMP’ed Up on the IEEE Low-Power Standard
  • Prologue: The 2012 Wilson Research Group Functional Verification Study
  • March 2013
  • Even More UVM Debug in Questa 10.2
  • IEEE Approves New Low Power Standard
  • February 2013
  • Verification Horizons DVCon Issue Now Available
  • Get your IEEE 1800-2012 SystemVerilog LRM at no charge
  • IEEE 1800™-2012 SystemVerilog Standard Is Published
  • See You at DVCon 2013!
  • Get Ready for SystemVerilog 2012
  • January 2013
  • VHDL Update Comes to Verification Academy!
  • December 2012
  • IEEE Approves Revised SystemVerilog Standard
  • November 2012
  • Coverage Cookbook Debuts
  • October 2012
  • IoT: Internet of Things
  • Check out the October, 2012 Verification Horizons
  • Improving simulation results with formal-based technology
  • Introducing “Verification Academy 2.0”
  • September 2012
  • OVM Gets Connected
  • August 2012
  • OpenStand & EDA Standardization
  • July 2012
  • Synthesizing Hardware Assertions and Post-Silicon Debug
  • Virtual Emulation for Debugging
  • Verification Academy: Up Close & Personal
  • SystemC Standardization Cycle Completes
  • Verification Standards Take Another Step Forward
  • New UVM Recipe of the Month: Scoreboarding in UVM
  • June 2012
  • Intelligent Testbench Automation – Catching on Fast
  • May 2012
  • Two Articles You Need to Check Out
  • Off to DAC!
  • Dave Rich Featured on EEWeb
  • March 2012
  • How Did I Get Here?
  • February 2012
  • Expanding the Verification Academy!
  • Get on the Fast Track to Advanced Verification with UVM Express
  • Introducing UVM Connect
  • Tornado Alert!!!
  • UVM: Some Thoughts Before DVCon
  • UVM™ at DVCon 2012
  • January 2012
  • SystemC 2011 Standard Published
  • Verification solutions that help reduce bug cost
  • December 2011
  • Instant Replay for Debugging SoC Level Simulations
  • 2011 IEEE Design Automation Standards Awards
  • November 2011
  • Getting started with the UVM – Using the Register Modeling package
  • TLM Becomes an IEEE Standard
  • October 2011
  • Worlds Standards Day 2011
  • VHS or Betamax?
  • Verification Issues Take Center Stage
  • September 2011
  • New UVM Recipe-of-the-Month: Sequence Layering
  • July 2011
  • Combining Intelligent Testbench Automation with Constrained Random Testing
  • Going from “Standards Development” to “Standards Practice”
  • Verification Academy Now Includes OVMWorld Content
  • June 2011
  • Intelligent Testbench Automation Delivers 10X to 100X Faster Functional Verification
  • Part 9: The 2010 Wilson Research Group Functional Verification Study
  • Verification Horizons DAC Issue Now Available Online
  • Accellera & OSCI Unite
  • The IEEE’s Most Popular EDA Standards
  • UVM Register Kit Available for OVM 2.1.2
  • May 2011
  • Part 8: The 2010 Wilson Research Group Functional Verification Study
  • Getting Your Standards Update @ DAC 2011
  • April 2011
  • User-2-User’s Functional Verification Track
  • Part 7: The 2010 Wilson Research Group Functional Verification Study
  • Part 6: The 2010 Wilson Research Group Functional Verification Study
  • SystemC Day 2011 Videos Available Now
  • Part 5: The 2010 Wilson Research Group Functional Verification Study
  • Part 4: The 2010 Wilson Research Group Functional Verification Study
  • Part 3: The 2010 Wilson Research Group Functional Verification Study
  • March 2011
  • Part 2: The 2010 Wilson Research Group Functional Verification Study
  • Part 1: The 2010 Wilson Research Group Functional Verification Study
  • Prologue: The 2010 Wilson Research Group Functional Verification Study
  • Language Transitions: The Dawning of Age of Aquarius
  • Using the UVM libraries with Questa
  • February 2011
  • DVCon: The Present and the Future
  • Free at Last! UVM1.0 is Here!
  • Parameterized Classes, Static Members and the Factory Macros
  • IEEE Standards in India
  • January 2011
  • Accellera Approves New Co-Emulation Standard
  • December 2010
  • New Verification Horizons: Methodologies Don’t Have to be Scary
  • The Survey Says: Verification Planning
  • October 2010
  • Towards UVM Register Package Interoperability
  • IEC’s 47th General Assembly Meeting Opens
  • UVM: Giving Users What They Want
  • September 2010
  • UVM Takes Shape in the Accellera VIP-TSC
  • Accellera VIP-TSC Selects RAL for UVM 1.0 Register Package
  • OVM Cookbook Available from OVMWorld.org
  • UVM Register Package Candidate News
  • August 2010
  • Redefining Verification Performance (Part 2)
  • July 2010
  • Making formal property checking easy to use
  • Redefining Verification Performance (Part 1)
  • SystemVerilog Coding Guidelines: Package import versus `include
  • June 2010
  • The reports of OVM’s death are greatly exaggerated (with apologies to Mark Twain)
  • New Verification Academy Advanced OVM (&UVM) Module
  • OVM/UVM @DAC: The Dog That Didn’t Bark
  • DAC: Day 1; An Ode to an Old Friend
  • UVM: Joint Statement Issued by Mentor, Cadence & Synopsys
  • Static Verification
  • OVM/UVM at DAC 2010
  • DAC Panel: Bridging Pre-Silicon Verification and Post-Silicon Validation
  • Accellera’s DAC Breakfast & Panel Discussion
  • May 2010
  • Easier UVM Testbench Construction – UVM Sequence Layering
  • North American SystemC User Group (NASCUG) Meeting at DAC
  • An Extension to UVM: The UVM Container
  • UVM Register Package 2.0 Available for Download
  • Accellera’s OVM: Omnimodus Verification Methodology
  • High-Level Design Validation and Test (HLDVT) 2010
  • New OVM Sequence Layering Package – For Easier Tests
  • OVM 2.0 Register Package Released
  • OVM Extensions for Testbench Reuse
  • April 2010
  • SystemC Day Videos from DVCon Available Now
  • On Committees and Motivations
  • The Final Signatures (the meeting during the meeting)
  • UVM Adoption: Go Native-UVM or use OVM Compatibility Kit?
  • UVM-EA (Early Adopter) Starter Kit Available for Download
  • Accellera Adopts OVM 2.1.1 for its Universal Verification Methodology (UVM)
  • March 2010
  • The Art of Deprecation
  • OVM 2.1.1 Now Ready for Download
  • February 2010 Verification Horizons Newsletter Now Available
  • IEEE Standards Meetings in India
  • February 2010
  • I Do It …
  • SystemVerilog: A time for change? Maybe not.
  • Partners Offer Support for OVM 1.0 Register Package
  • SystemC Day at DVCon
  • OVM/VMM Interoperability Kit: It’s Ready!
  • January 2010
  • Three Perfect 10’s
  • OVM 1.0 Register Package Released
  • Accellera Adopts OVM
  • SystemC (IEEE Std. 1666™) Comes to YouTube
  • Debugging requires a multifaceted solution
  • December 2009
  • A Cliffhanger ABV Seminar, Jan 19, Santa Clara, CA
  • Truth in Labeling: VMM2.0
  • IEEE Std. 1800™-2009 (SystemVerilog) Ready for Purchase & Download
  • December Verification Horizons Issue Out
  • Evolution is a tinkerer
  • It Is Better to Give than It Is to Receive
  • Zombie Alert! (Can the CEDA DTC “User Voice” Be Heard When They Won’t Let You Listen)
  • DVCon is Just Around the Corner
  • The “Standards Corner” Becomes a Blog
  • I Am Honored to Honor
  • IEEE Standards Association Awards Ceremony
  • ABV and being from Missouri…
  • Time hogs, blogs, and evolving underdogs…
  • Full House – and this is no gamble!
  • Welcome to the Verification Horizons Blog!
  • September 2009
  • SystemVerilog: The finer details of $unit versus $root.
  • SystemVerilog Coding Guidelines
  • July 2009
  • The Language versus The Methodology
  • May 2009
  • Are Program Blocks Necessary?